The film is set in 1913 Russia during the celebrations of the Tricentennial Anniversary of the Romanov Dynasty. Rich Russian merchants are celebrating their wealth by gambling and playing poker. They are traveling aboard the luxurious cruise liner "St. Nikolai" on Volga river, oblivious to the fact that several gangs of crooks and con-artists are stealing their money in the game. Their target is the wealthiest Russian tycoon Satanovsky.
A flutist in the forgotten past, at present the husband of a “big man’s” daughter and head of one of the Chief Directorate’s sections felt unwell one day: the forty-year-old man had a pain in his heart. This unpleasant incident provided an opportunity to meet a nurse named Lida. However, their stormy love affair ended, with Filimonov returning to normal life and an unloved wife.
In one of the realms, there was time for the prince to get married, but the bride would have to be a real princess. A sign was put up on the gates: “ A Princess Wanted”. But in response to it there appeared only a small girl, wet to the bones after the rain and bearing no resemblance to nobility. So the prince was obliged to venture off to other lands in search of a suitable match. Henceforth the prince’s adventures unfold. In one kingdom, he met a fat king, in another – a hospitable king. He also visited the kingdom of arts. He saw enough princesses, beautiful and clever. And yet, the real princess, the only one he longed for, proved to be the girl who had knocked at their door during a rainstorm…